Hazardous chemicals and radioactive substances have permeated the human environment and the ecosystem. They are now in our basic life support systems – air, water, food and soil. A matter of more serious concern is that human beings have been exposed to synthetic chemicals for which there has been no past evolutionary adaptation or experience. Any chemical which interferes directly or indirectly with hormone function can scramble vital messages, derail development and undermine health. This book highlights the scientific research being done to identify these harmful chemicals, especially carcinogens, teratogens, immunotoxins and endocrine disruptors used in production processes and their release into the human environment, making it possible to restrict or even eliminate their production and use.